You are given a large number made of only 0’s and 1’s.Your task is to find the max no of consecutive 1’s. If there are no 1’s print -1

You are given a large number made of only 0’s and 1’s.Your task is to find the max no of consecutive 1’s. If there are no 1’s print -1

Input Description:
A large number ‘n’

Output Description:
Print the max no of consecutive 1 in the number

Sample Input :
101011111
Sample Output :
5



n=input()
res=(max(map(len,n.split('0'))))
if res>=1:
  print(res)
else:
  print("-1")